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A174790
Triangle read by rows: T(n,m) = 1 + ((-1 + binomial(n, m))*(n!)^2)/(m!*(n - m)!).
2
1, 1, 1, 1, 5, 1, 1, 37, 37, 1, 1, 289, 721, 289, 1, 1, 2401, 10801, 10801, 2401, 1, 1, 21601, 151201, 273601, 151201, 21601, 1, 1, 211681, 2116801, 5997601, 5997601, 2116801, 211681, 1, 1, 2257921, 30481921, 124185601, 194745601, 124185601, 30481921, 2257921, 1
OFFSET
0,5
FORMULA
T(n,m) = ((n!)^2/(m!*(n - m)!))*binomial(n, m) - ((n!)^2/(m!*(n - m)!)) + 1.
From Stefano Spezia, Dec 18 2018: (Start)
T(n,m) = 1 + ((binomial(n, m) - 1)*(n!)^2)/(m!*(n - m)!).
T(n,m) = 1 + ((A007318(n, m) - 1)*A001044(n))/(A000142(m)*A000142(n - m)). (End)
EXAMPLE
Triangle begins:
1
1 1
1 5 1
1 37 37 1
1 289 721 289 1
1 2401 10801 10801 2401 1
1 21601 151201 273601 151201 21601 1
...
MATHEMATICA
T[n_, m_] := (n!^2/(m!(n - m)!))*Binomial[n, m] - (n!^2/(m!(n - m)!)) + 1; Flatten[Table[Table[T[n, m], {m, 0, n}], {n, 0, 10}]]
PROG
(GAP) Flat(List([0..10], n->List([0..n], m->1 + ((- 1 + Binomial(n, m))*(Factorial(n)^2)/(Factorial(m)*Factorial(-m+n))))
)); # Stefano Spezia, Dec 18 2018
(PARI)
T(n, m)= 1 + ((- 1 + binomial(n, m))*(n!)^2)/(m!*(-m+n)!);
tabl(nn) = for(n=0, nn, for(m=0, n, print1(T(n, m), ", ")); print);
tabl(10) \\ Stefano Spezia, Dec 18 2018
CROSSREFS
Cf. A320329 (row sums).
Sequence in context: A015116 A367380 A322220 * A156691 A246051 A111820
KEYWORD
nonn,tabl,easy
AUTHOR
Roger L. Bagula, Mar 29 2010
EXTENSIONS
Edited by Stefano Spezia, Dec 18 2018
STATUS
approved